The invention relates generally to cooling systems and more specifically to water-cooled remote fan drives.
Cooling -systems are used on vehicles today to provide cooling to an engine during operation. Fan drives are typically driven by the engine crankshaft at a fixed ratio to cool engine coolant as it flows through a radiator. Thus, as the engine speed is reduced, as is the trend in vehicles today to reduce emissions, the fan drive speed is correspondingly reduced. Similarly, as the engine speed increases, the fan drive speed correspondingly increases.
Many cooling systems, for example truck cooling systems, suffer from inefficient or insufficient cooling capabilities. For example, many cooling systems suffer from insufficient idle and peak air cooling, poor fan efficiencies, no or inadequate fan drive pulley ratios, and/or poor fan orientation relative to radiators.
It is thus highly desirable to create extra overdrive in a cooling system to improve the cooling capabilities of cooling systems to overcome some of the above described prior art deficiencies. The proposed system should be able to be used with currently available engine and radiator locations, should allow a minimum radial displacement between an engine and a radiator, should allow for axial motion of the engine, should maximize fan size within a predetermined packaging volume, and have a predetermined torque capability for driving the fan.
The above and other objects of the invention are met by the present invention that is an improvement over known fan drive systems.
The present invention incorporates an additional pulley that is either mounted on the shroud of the radiator or mounted to the front of the water pump and crank pulleys. This additional pulley is sized smaller than the crank pulley to create extra overdrive. This allows the fan to rotate at a faster speed, which improves the cooling efficiency of the radiator. Further, these remote fan drives are water-cooled by making them integral to the water pump or by coupling them to the water pump to improve heat dissipation and reduce weight and packaging size. In an alternative arrangement, more than one additional pulley may be added.
Further, in the case of the fan mounted on the shroud, this system provides a shroud mounted fan with high efficiencies due to tight blade tip clearance, ideal fan orientation, and large overdrive ratio options because of water-cooled heat dissipation. Also, there is the potential for using dual fans in these systems, which could also improve fan efficiency and fan orientation.
Other features, benefits and advantages of the present invention will become apparent from the following description of the invention, when viewed in accordance with the attached drawings and appended claims.